At the time of an ophthalmic surgical operation, a knife or trocar is employed to pierce an eyeball or incise a cornea or sclera, and a suture needle for piercing or incising a muscle or a skin is employed to suture an affected area. A medical cutting tool such a knife, a trocar, or a suture needle includes a sharp tip, a sharp edge elongated from the sharp tip, a plane portion that forms the edge, and a body portion continuously elongated from the plane portion.
The edge and the plane portion have cross sections having a polygonal shape such as a triangle, a rectangle, or a pentagon. The shape of the cross section is set according to a type of a desired medical cutting tool, that is, according to whether the medical cutting tool is a knife, a trocar, or a suture needle. In addition, regardless of the cross-sectional shape of the medical cutting tool, two edges are formed by using the sharp tip as a starting point (for example, see Patent Literature 1).